Start by heating a large skillet over medium heat. Add the ground beef and cook until it's browned, breaking it apart with a spatula as it cooks. Drain off any excess fat.

Once the beef is browned, add the diced onion and minced garlic. Sauté until the onion is translucent.

Incorporate the refried beans, chili powder, cumin, salt, and black pepper. Stir to combine and cook until heated through, about 3 to 5 minutes.

Remove from heat and fold in the shredded cheddar cheese until it melts and integrates smoothly with the mixture.

Prepare your tortillas by laying one flat on a clean surface. Spoon about a quarter of the filling in the center, fold the sides over, and roll tightly.

Repeat this process for the remaining tortillas and filling.

In a deep skillet, pour enough oil for frying and heat over medium-high. Once hot, carefully place the chimichangas seam side down.

Fry for about 3-4 minutes on each side or until golden brown. Remove and let drain on paper towels.

Serve the chimichangas warm, garnished with sour cream and salsa.